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Brake Vacuum reservoir Question for Ken H [message #71035] Sun, 17 January 2010 12:11 Go to next message
Matt Colie is currently offline  Matt Colie   United States
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I thought long and hard about posting this as a private message to Ken, but I have decided that I am probably not the only one interested in the answer.

After beating up the search engine, I could not locate an answer if it was ever posted.

Ken,
As you did build and install the reservoir pictured in:

URL<http://www.gmcmhphotos.com/photos/showphoto.php?photo=3868&cat=3056>

Can you give an impression of how many pedal strokes you now get before the required load goes high??

I find this a much more interesting add-on than a electric vacuum pump as it has only one additional part to possibly fail (and the electric option has about a dozen).

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] Brake Vacuum reservoir Question for Ken H [message #71037 is a reply to message #71035] Sun, 17 January 2010 12:26 Go to previous messageGo to next message
comcast is currently offline  comcast   United States
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Registered: August 2009
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Senior Member
Matt,
I get 5 or 6 good pumps off of mine if I recall correctly. It's hard
to define how many you'll get because of different lengths of the
tubes and also the number of tubes. I have two, but not sure of the
length of them. One is mounted in front of crossmember and the other
behind.

The most important thing is the tube itself. The thin walled stuff
WILL FLATTEN from the vacuum. Don't ask! Just take my word for it.

Roger
Burns, TN


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Re: [GMCnet] Brake Vacuum reservoir Question for Ken H [message #71040 is a reply to message #71035] Sun, 17 January 2010 13:23 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Location: Sydney, Australia
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Matt,

I agree and am going to add a reservoir to the pump in Double Trouble in the
USA.

Unfortunately I have a problem here in Australia as all the plumbing is
metric and therefore I can't get 4" schedule 40 pipe: hopefully 100mm pipe
will work as well.

I will be able to conduct some comparison testing as I have the same pump
installed in The Blue Streak here in Australia.

I will report my findings as it may help determine if the metric system is a
better way of making measurements.

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Matt Colie
Sent: Monday, 18 January 2010 5:12 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] Brake Vacuum reservoir Question for Ken H

I thought long and hard about posting this as a private message to Ken, but
I have decided that I am probably not the only one interested in the answer.


After beating up the search engine, I could not locate an answer if it was
ever posted.

Ken,
As you did build and install the reservoir pictured in:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=3868&cat=3056

Can you give an impression of how many pedal strokes you now get before the
required load goes high??

I find this a much more interesting add-on than a electric vacuum pump as it
has only one additional part to possibly fail (and the electric option has
about a dozen).

Matt

--
Matt & Mary Colie
'73 Glacier 23 Chaumiere (say show-me-air)
SE Michigan
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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Brake Vacuum reservoir Question for Ken H [message #71051 is a reply to message #71035] Sun, 17 January 2010 15:32 Go to previous messageGo to next message
GMCWiperMan is currently offline  GMCWiperMan   United States
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Matt,

I agree with you about reliability -- the reservoir's not likely to rust up
and fail to power up when you think it's there to help. It may even give
you more braking capability: IIRC, the boost pump shuts off at 18"Hg. The
reservoir will hold the highest vacuum the engine's created since the last
brake application -- probably over 20"Hg and maybe 29"+. Maybe 30% more
braking force.

I only claim about 3 more pedal applications. I think Bob deK claimed about
6 with his longer reservoir. As you realize, each application is a little
weaker than the one before so a definite answer's not possible without some
precise measurements that wouldn't mean anything in this real world.

Remember that 725' to stop from 55 mph on level ground with no boost. If
the engine quits, put the brakes on, KEEP them on, and PARK. :-)

Ken H.
Americus, GA
'76 X-Birchaven
www.gmcwipersetc.com


On Sun, Jan 17, 2010 at 1:11 PM, Matt Colie <mcolie@chartermi.net> wrote:

>
>
> I thought long and hard about posting this as a private message to Ken, but
> I have decided that I am probably not the only one interested in the answer.
>
> After beating up the search engine, I could not locate an answer if it was
> ever posted.
>
> Ken,
> As you did build and install the reservoir pictured in:
>
> URL<http://www.gmcmhphotos.com/photos/showphoto.php?photo=3868&cat=3056>
>
> Can you give an impression of how many pedal strokes you now get before the
> required load goes high??
>
> I find this a much more interesting add-on than a electric vacuum pump as
> it has only one additional part to possibly fail (and the electric option
> has about a dozen).
>
> Matt
>
>
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Re: Brake Vacuum reservoir Question for Ken H [message #71089 is a reply to message #71035] Sun, 17 January 2010 23:12 Go to previous messageGo to next message
zhagrieb is currently offline  zhagrieb   United States
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Registered: August 2009
Location: Portland Oregon
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Senior Member
I made a reservoir of 4" PVC and connected it with a single "T" fitting to the line between manifold and brake booster. I put a check valve in the live between the manifold and the "T". I have no idea haw many pumps it gives me but more than enough to stop the coach.

Glenn Giere


Glenn Giere, Portland OR, K7GAG '73 "Moby the Motorhome" 26'
Re: [GMCnet] Brake Vacuum reservoir Question for Ken H [message #71091 is a reply to message #71040] Mon, 18 January 2010 00:01 Go to previous messageGo to next message
GMCWiperMan is currently offline  GMCWiperMan   United States
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Registered: December 2007
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Senior Member
Rob,

Here's your plumbing diagram:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=32209&title=brake-vacuum-reservoir&cat=3056
<http://www.gmcmhphotos.com/photos/showphoto.php?photo=32209&title=brake-vacuum-reservoir&cat=3056>
Ken
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Re: [GMCnet] Brake Vacuum reservoir Question for Ken H [message #71098 is a reply to message #71091] Mon, 18 January 2010 05:23 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Registered: July 2007
Location: Sydney, Australia
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Ken,

Thanks!

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Ken Henderson
Sent: Monday, 18 January 2010 5:01 PM
To: gmclist
Subject: Re: [GMCnet] Brake Vacuum reservoir Question for Ken H

Rob,

Here's your plumbing diagram:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=32209&title=brake-vacu
um-reservoir&cat=3056
<http://www.gmcmhphotos.com/photos/showphoto.php?photo=32209&title=brake-vac
uum-reservoir&cat=3056>
Ken
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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
vacuum for HVAC? [message #71106 is a reply to message #71091] Mon, 18 January 2010 08:26 Go to previous messageGo to next message
bukzin is currently offline  bukzin   United States
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Location: North California
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That diagram also shows a connection to the dash HVAC system.

So that would be addition/back-up vacuum to operate
the control pots. Is that correct?


Bukzin
1977 Palm Beach

[Updated on: Mon, 18 January 2010 08:56]

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Re: [GMCnet] vacuum for HVAC? [message #71107 is a reply to message #71106] Mon, 18 January 2010 08:47 Go to previous message
GMCWiperMan is currently offline  GMCWiperMan   United States
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Registered: December 2007
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Senior Member
That's right, Richard. But, as I mentioned, the effect on my HVAC was such
that it wasn't worth the trouble of drilling the 1/4" hole, much less the
cost of 2' of vacuum hose.

Ken H.


On Mon, Jan 18, 2010 at 9:26 AM, Richard <bukzin@gmail.com> wrote:

>
>
> That diagram also shows a connection to the dash HVAC system.
>
> So that would be addition/back-up vacuum to operate
> the control control pots. Is that correct?
> --
>
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